This invention relates to the encoding of data. More particularly, it relates to a method of encoding data, an encoding means for encoding data, a method of decoding data, a decoding means for decoding data and a carrier with data encoded thereon.
The invention has particular application to cards with a magnetic strip thereon. Such cards have been encoded in a binary manner in a standardised way, in accordance with ISO standard 3554. In this manner of encoding, a cell is defined by a transition at the beginning of the cell and at the end of the cell, with a transition defining the end of one cell and the beginning of the next. A "1" and a "0" are defined by the presence or absence of a further transition in the center of the cell.
Those skilled in the art will be aware that magnetic cards are encoded with a number of leading and trailing 0's.
In essence, the invention implements a higher order of symbology than binary, to provide a trinary, quaternary, or higher order symbology. This is effected by using more than one internal transition position in each cell.